FI86408C - Bearing unit for support rollers in a horizontal oven and a horizontal oven for glass slabs - Google Patents

Description

1 86408

The present invention relates to a horizontal oven support roller bearing unit for heating glass sheets and treating sheets heated to tempering and / or conveying temperature, wherein the furnace has at least a series of support rollers for synchronous use.

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Numerous embodiments of a horizontal furnace are known in the art, which generally differ in terms of roller coupling and drive devices and roller bearings. Conventional embodiments are disclosed, for example, in EP-51,539, EP-70,244, DE-2,319,049, DE-2,605,303, US-4,230,475, US-4,399,598 and US-4,725,300.

In the hot zone of such horizontal furnaces, the support rollers or cylinders forming the conveyor track usually consist of 20 cylindrical ceramic tubes or rods, the end portions of which are passed through the side walls of the furnace outside the furnace and mounted on bearings arranged outside the furnace. Bearing of the support rollers to the bearings fitted inside the furnace is not possible by known means: \% 5 due to the temperatures in the furnace above 600 ° C. national; , · Outside the oven, the rollers are connected to the drive “V in a suitable way and operated synchronously.

'• * • 30 different implementations are known for bearing support rollers outside the furnace. According to U.S. Pat. No. 4,399,598, metal plugs are pressed into each end of the ceramic tubes: and each supports the shaft end. These shaft ends bear::: conventional ball bearings. EP patent publications- ‘. according to sun 51 539, each of the end parts of the support rollers is mounted ... 35 outside the furnace to rotate freely on two steel rollers arranged close to each other in a horizontal *; ** plane.

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In addition, according to DE-2 319 049 and DE-2 605 303, the end zones of the support rolls located outside the furnace are arranged on synchronously pulled belts, which in turn slide on flat support surfaces. In the direction of movement of the belts 5, behind the support rollers, abutments or stop rollers are arranged, against which the support rollers rotate and by means of which the support rollers maintain their position during their rotational movement. The use of the support rollers takes place by static friction caused by the weight of the rollers between the moving belts 10 and the support rollers placed on these belts.

In order to preserve the optical properties of the glass sheets, there must be as little deviation as possible in the support lines of the rolls in the zone of the oven 15 where the glass sheets reach or exceed their softening temperature. This means that the support rollers must have the smallest possible diameter; in practice, closely spaced support rollers with a diameter of 4-5 cm are used.

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As the width of the oven increases, which is necessary for heating or processing larger glass sheets, it becomes more difficult to maintain the desired high optical quality of the glass panes. This is because, as their length increases while the diameter remains the same, f support rolls exhibit increasing elastic bending due to their own weight and possibly permanent deformations. As a result, the upper straight lines I J are no longer optimally located in the same and only plane, and '30 this more or less uneven support of the glass sheets leads to a noticeable deterioration in the flatness of the glass panes' · "and a change in their optical properties.

Although a stretching plant is known from DE 615 421, •• 1.35 in which roller bearings are arranged inside the furnace, but this type of furnace has a substantially lower temperature than in a convex-tempering furnace. By known means, it is not possible to eliminate the above-mentioned disadvantages by placing the bearings of the support rollers in a heating space.

The object of the invention is to provide a bearing for a support roll, which on the one hand has better rotation properties than known bearings and on the other hand can be used at clearly higher temperatures than these. More particularly, it is an object of the invention to provide a bearing which can withstand any rising heat inside the furnace itself, so that the free length of the two support rollers between the two bearings decreases while the working width of the furnace remains the same, and the support level accuracy is reduced.

According to the invention, these objects are achieved in that the bearing unit consists of a bearing which automatically adapts to the cross-sectional direction of the roll and which supports two pins each having a substantially point support surface, one pin fixedly and pivotally mounted and the other pin mounted on a flat base, that it can rotate by sliding around a fixed pin, and that the bearing sliding surface has openings into which a pressurized gas is fed into the bearing gap between the bearing and the roll to form a gas film, "• ^ 5 in particular air.

The invention provides a bearing unit in which, due to the gas support of the roll, no mechanical contact is created between the surfaces moving relative to each other. Thus, there is no me-'30 cap contact inside the bearing. The permanent gap required to form a smooth gas film between the surface of the roll and the surface of the bearing is ensured by a bearing support which is flexible and automatically adapts to the roll. The fact that ·; ··; the bearing supports only two points located. * •• .35 in a line perpendicular to the axis of the roll, allows • on the one hand a pivoting movement of the bearing around the connecting line and on the other hand a horizontal rotational movement around the fixed pivot 4 86408. Thus, the bearing positions itself optimally.

This self-positioning of the bearing allows the bearings to be installed inside the oven. When the furnace is heated, thermal expansion of the substances inevitably occurs, which requires adjustment of the bearings, but it is self-evident that manual adjustment cannot be performed inside the hot furnace.

In addition, the roller bearing units according to the invention can considerably shorten the free length of the rollers between two bases with respect to the effective width of the same furnace. Thus, the risk of bending the support rollers is greatly reduced. It is even possible to use smaller diameter support rollers, and thus a larger number, to increase the number of glass sheet bases, reducing the risk of deformation. When choosing a very dense arrangement of the support rollers, the bearings can be placed at an oblique cross, i.e. alternately in two adjacent rows.

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The invention also provides a furnace for heating glass sheets, characterized in that in at least part of the furnace the roller supports are arranged inside the furnace and consist of gas bearing units with openings in the sliding surfaces supplied with a pressurized gas, in particular air, to form a gas film between the bearing and the roll. -rointiväliin. The rollers are preferably shorter in length than the width of the oven and mounted completely inside it.

.30 A horizontal furnace with a combination of these characteristics shall optimally meet the requirements for high optical quality of glass panes and, in addition, enable industrial mass production. Costs will be significantly reduced due to. shortening of rolls, which are usually made of expensive -35 raw material.

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In addition, openings in the oven wall for the use of rollers are minimized; thus the heat losses are very small and a homogeneous temperature profile in the furnace is obtained.

Further details and preferred features of the invention are set forth below with reference to the accompanying figures: Figure 1: an overall view of the support roller bearing unit in a fragmentary perspective view; Fig. 2: a sectional view of the bearing unit according to Fig. 1; Fig. 3: a partial perspective view of a glass-plate continuous furnace with rotatably mounted support rollers according to the invention; As can be seen in detail in Figures 1 and 2, the bearing unit comprises a resiliently supported bearing 1 which rests on a rectangular tube 2 which at the same time supplies compressed air.

20 The bearing 1 is a refractory metal or some other refractory material, for example ceramic. It is sleek, i.e. the sliding surface 3 supporting the support roller 27 is in the shape of a semi-cylinder with a semi-circular bottom surface. The sliding surface 3 opens with openings 4, 5 through which compressed air enters the bearing gap.

The bearing 1 is supported by two pins 8, 9 screwed into threaded holes 10, 11 which are extended by the threads! threaded holes 12, 13. The threaded holes 10, 11 are fitted in the vertical median plane of the bearing, while the holes 12, 13 pass through the rest of the bearing housing. The upper surface of each pin 8, 9 has an inwardly hexagonal recess 14.

• The screwing depth of the pins 8, 9 to the threaded holes 10, 11 -: can then be changed with the help of hexagonal wrenches.

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The lower end of the pin 8 has a spherical end 16 and the pin 9 a spherical end 17. The spherical end 17 forming the support surface of the fixed support member, i.e. the pin 9, rests on a corresponding spherical dome consisting of a threaded cylindrical sleeve 18 and a cylinder 19 screwed into this sleeve 18 has a bearing surface 20 having the shape of a hollow spherical segment and cooperating with the support surface of the spherical head 17. The laterally spherical head 17 is guided by the inner wall of the sleeve 18. The pin 9 forming the fixed support 10 of the bearing can thus perform pivoting movements in the spherical housing 18, 19, 20 at an angle around the spherical head 17 in all directions. The upper end of the sleeve 18 has a shoulder 21. The sleeve 18 with the screwed cylinder 19 is inserted into an opening 22 which is fitted in the upper wall 23, 15 of the rectangular tube 2, whereby the shoulder 21 supports the wall 23.

The pin 8 with the spherical end 16 slidably forms the support of the rotating bearing. The spherical end 16 supports the wall 23 of the rectangular tube 2 on a flat surface.

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The entry of the support gas, for example air, into the bearing gap formed by the surface 3 and the cutting surface of the roller 27 rotating in the bearing takes place by means of a rectangular tube 2 through a fixed pin 9. The cylinder 19 and the pin 9 each have an axial bore 28 for this purpose.

Inside the bearing there is a hole 13 which is perpendicular to the shape 30 and transverse to it, to which is connected two openings 5 opening into the bearing surface 3. Similarly, in connection with the transverse shape 30 there is a shape 31 extending parallel. . with the hole 13, which in turn communicates with the longitudinal bore 32. The longitudinal bore 32 opens into the transverse bore 33, with which two openings 4 opening into the bearing surface 3 communicate. The bores 30, 31, 32 .35 and 33 form recesses and they are closed by suitable plugs, pat 34. The hole 13 is closed by a plug 35 screwed from the top, which can be removed if necessary for adjusting the height of the pin 9. With this li 7 86408 drilling system, compressed air can be supplied to the bearing gap.

Fig. 3 shows a horizontal furnace 38 for glass sheets and illustrates 5 how the free length of the support rollers 39 can be shortened so that the described bearing units are located inside the furnace as heat-resistant bearings. For this purpose, rectangular tubes 2 of refractory steel are arranged along the side walls of the furnace. Each rectangular tube 2 is supplied with compressed air through a supply tube 40. Bearings 1 are fitted to the rectangular tubes 2 as described above. The support rollers 39 are led to the outside of the furnace on one side thereof through openings 42 arranged in the respective side wall 41. A gear 44 is attached to the end zone 43 of each support roller 39, 15 which rolls, for example, of a ceramic cylinder or tube. The gears 44 are rotated by a chain 46 driven by a motor 45. The chain 46 is held in place by a flat base 47 on which it slides.

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It is usually sufficient for the compressed air introduced into the pipes 2 to be at room temperature. In this way, it is also possible to cool more or less bearing units and the sections of the support rollers 39 mounted on the bearings. However, when paying attention to a particularly flat temperature curve, the ____. the pressure allowed in the pipes 2 can be heated inside the nin; air to the desired temperature.

---- Such a horizontal furnace is specially designed for heating glass sheets:. * .: 30 for shaping and / or tempering them, specifically for the manufacture of automotive windscreens.

Claims (9)

A support roller bearing unit for horizontally heated glass sheets, in particular for conveying and tempering them, characterized in that the bearing unit consists of a bearing (1) which automatically adapts to the cross-sectional direction of the roller (27) and supports two pins (8, 9) , each having a substantially pointing support surface, the second pin (9) being fixedly and pivotally mounted and the second pin (8) being mounted on a flat base so as to be able to rotate by sliding around the fixed pin (9), and that the bearing (1) the sliding surface (3) has openings (4, 5) into which a pressurized gas, in particular air, is fed into the bearing gap between the bearing (1) and the roll to form a gas film. 15 Bearing unit according to Claim 1, characterized in that the substantially point-like support surfaces of the pins (8, 9) are each in the shape of a spherical head (16, 17). Bearing unit according to Claim 2, characterized in that the spherical end (17) of the fixed pin (9) is rotatably mounted in the spherical housing (20). Bearing unit according to one of Claims 1 to 3, characterized in that the entry of air into the openings of the bearing (1):. (4, 5) takes place via an axial bore (28) in the fixed support (pin 9), and that the bearing part (cylinder 19) forming the spherical housing (20) is also provided with an axial bore (28) which communicates with the air • -30 to the supply line (2). Bearing unit according to one of Claims 1 to 4, characterized in that the pins (8, 9) of the bearing (1) are mounted on a rectangular line (2) supplying compressed air, the flat top wall (23) of which forms a direct mounting surface on the support (pin 8). , which can rotate slidably, and on which a support (18, 19, 20, 21) is mounted, which supports a fixed support (pin 9). 9 864C8 Bearing unit according to one of Claims 1 to 5, characterized in that the supports with point support surfaces or in the form of spherical ends consist of pins (8, 9) whose screwing depth to the bearing (1) is adjustable. Bearing unit according to Claim 6, characterized in that the bearing (1) has via holes 10 (12, 13) in the extension of the threaded holes (10, 11) receiving the pins (8, 9), through which the screwing depth of the pins (8, 9) can be adjusted. . Horizontal furnace for heating glass sheets, in particular for conveying and / or tempering them, comprising support rollers (27) used synchronously, characterized in that bearing units are used for the support rollers (27), each of which consists of a bearing (1) which automatically adapts to the roll. (27) according to the cross-sectional direction and supporting two pins (8, 9) each having a substantially 20 point support surface, the second pin (9) being fixedly and pivotally mounted and the second pin (8) mounted on a flat base so as to be accessible rotating as it slides around the fixed pin (9), and that the sliding surface (3) of the bearing (1) has openings (4, 5) which are fed into the bearing gap between the bearing (1) and the roll to form a gas film. with pressurized gas, especially-. ^ ti with air, the bearing units (1) being mounted inside the furnace and on the pipes (2), which pipes are arranged along the side walls of the furnace and through which the bearing units ‘•’ • 30 are supplied with compressed air. 8 864C8 Horizontal oven according to Claim 8, characterized in that the length of the support rollers (27) is less than the width of the oven. ; 35 10 86408